Adds Initial Support For Multi-Backend Sensors

[AntoineRichard]

Description

This PR extends the multi-backend architecture to the sensor classes (ContactSensor, Imu, FrameTransformer) following the same pattern established for asset classes in the antoiner/multi-backend branch.

• Created abstract base classes for sensors in isaaclab:

  • BaseContactSensor and BaseContactSensorData
  • BaseImu and BaseImuData
  • BaseFrameTransformer and BaseFrameTransformerData

• Converted existing sensor classes and data classes to factory wrappers using the FactoryBase pattern

• Moved PhysX-specific sensor implementations to isaaclab_physx:

  • isaaclab_physx.sensors.ContactSensor and ContactSensorData
  • isaaclab_physx.sensors.Imu and ImuData
  • isaaclab_physx.sensors.FrameTransformer and FrameTransformerData

• Moved PhysX-specific sensor tests to isaaclab_physx/test/sensors/

Type of change

• New feature (non-breaking change which adds functionality)
• Breaking change (existing functionality will not work without user modification)

Checklist

• I have read and understood the contribution guidelines
• I have run the pre-commit checks with ./isaaclab.sh --format
• I have made corresponding changes to the documentation
• My changes generate no new warnings
• I have added tests that prove my fix is effective or that my feature works
• I have updated the changelog and the corresponding version in the extension's config/extension.toml file
• I have added my name to the CONTRIBUTORS.md or my name already exists there

[greptile-apps]

Too many files changed for review. (133 files found, 100 file limit)

[kellyguo11]

for ones that Newton or PhysX don't have support yet, might be useful to add a note in the docstring to mention Newton-only or PhysX-only so that when users look through the APIs, they'll know what to expect on which APIs will be available for their backend

[AntoineRichard]

Yes, that would be reasonable. Can it wait till the newton stack makes it in? It may have support for those things by then?